New research suggests having a stroke could age a person's brain by almost eight years.

Both black and white patients who had suffered a stroke and took a 27-item memory and cognition test showed scores that appeared as if they had aged 7.9 years overnight, the University of Michigan reported.

To make their findings the researchers looked at surveys and tests of memory and thinking speed from participants in a large, national study of elderly Americans, as well as Medicare data. They selected the 7.5 percent of black study participants, and

6.7 percent of white participants who had suffered a stroke within 12 years of their first cognition test but had no recent history of stroke. The researchers found patients in both groups performed worse on the tests following their stroke. Past research has shown rates of cognitive problems in older black individuals tend to be twice that of non-Hispanic whites, this new finding suggests stroke does not play a role in this disparity.

"As we search for the key drivers of the known disparities in cognitive decline between blacks and whites, we focus here on the role of 'health shocks' such as stroke," said lead author and U-M Medical School assistant professor Deborah Levine. "Although we found that stroke does not explain the difference, these results show the amount of cognitive aging that stroke brings on, and therefore the importance of stroke prevention to reduce the risk of cognitive decline."

The researchers urge people of all racial and ethnic backgrounds should make an effort to reduce their risk of stroke. Some strategies for reducing stroke risk are:" controlling blood pressure and cholesterol, stopping or avoiding smoking, controlling blood sugar in diabetes, and being active even in older age."

The findings were reported in a recent edition of the journal Stroke.